ide: add ide_execute_pkt_cmd() helper

Add ide_execute_pkt_cmd() helper for executing PACKET command,
then convert ATAPI device drivers to use it.

As a nice side-effect this fixes ide-{floppy,tape,scsi} w.r.t.
ide_lock taking (ide-cd was OK).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 7f2b4ed..dfe47d5 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -801,9 +801,19 @@
 	ndelay(400);
 	spin_unlock_irqrestore(&ide_lock, flags);
 }
-
 EXPORT_SYMBOL(ide_execute_command);
 
+void ide_execute_pkt_cmd(ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ide_lock, flags);
+	hwif->OUTBSYNC(drive, WIN_PACKETCMD, hwif->io_ports.command_addr);
+	ndelay(400);
+	spin_unlock_irqrestore(&ide_lock, flags);
+}
+EXPORT_SYMBOL_GPL(ide_execute_pkt_cmd);
 
 /* needed below */
 static ide_startstop_t do_reset1 (ide_drive_t *, int);